Mechanics

NOISE WHILE HITTING THE BRAKE WHEN NEAR A STOP.

2004 Volkswagen Passat • 92,000 miles

Hi, guys,

I just got another problem after I installed the new upper control arms and CV axles for both sides. I just made a video in order to describe this symptom more clearly. the mechanic told me that is because of the brake pad are new. However, this never happened before I installed the new parts on it.( I already have the brake pad for a while). please help me figure this out.....I will be so appreciated.

this happened only when I "ALMOST STOP" and pressing the brake.my foot can feel something when put it on the brake pedal, its like I'm against something..

the only thing they did to my car is..I think we did the tire rotation, new cv axles, new upper control arms (bushings). I think thats all. I am just afraid that I am destroying something which I don't know.......if I leave the problem there.

please see the video and hear the noise. the noise comes when I hit the brake

http://www.youtube.com/watch?v=lHXo_t1tiog
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Avatar
Changchingchi
October 7, 2012.




Hi, Thomas,

I ask them to remove and install again about the ABS sensors and also they did the reface for all rotors. Problems seems getting better, but the noise still there. They ask me to go there and have a computer-scanned. Will keep updating. Thanks for your helps.

Tiny
Changchingchi
Oct 9, 2012.
Thanks for the update!

Did they at least verify that my "guess" was correct? The noise
that you are hearing / feeling is the ABS activation?

The scan might not show a fault code. Remember, the ABS system is
triggered because the ABS Module "thinks" that one of the wheels
has stopped turning and because of that, it releases & applies
brake pressure rapidly and does not store a code because of that.

Thomas

Tiny
Exovcds
Oct 9, 2012.
I haven't taken a longer test drive. At least, it doesnt happen in 5 miles on the way to school. When they took a test drive, hit the brake very strongly and the noise came. (But when I hit it very slow, there was no noise for that moment). One of the mechanic said that is normal for some types of vehicle. Seems that now the problem only exist when hitting the brake very strongly and suddenly. Ps. I guess that it is just about the abs system. But they told me the abs system looks pretty normal, nothing wrong when they checked it. Forgive my bad english.

Tiny
Changchingchi
Oct 9, 2012.
Your English is fine, I'm German. I had to learn as well! : -)

ABS activation when pressing hard (on dry flat roads) is normal.
ABS activation when pressing soft (on gravel, wet / snow roads) is normal.
ABS activation when pressing soft (on dry flat roads) is not normal.

I can drive my car for several weeks and never feel the ABS. It
all depends on the road conditions.

If it continues to happen, especially on dry flat surfaces & at
low speeds, then something is still wrong.

Continue to monitor it and see what happens.

Good luck,

Thomas

Tiny
Exovcds
Oct 9, 2012.
One thing here is you said that they heard the noise with a strong application, that may be just he abs unit making the noise due to the application. Alot of gm cars make a whine/groan type of noise and it's only normal because it's the abs unit working.

Hmac300
Oct 9, 2012.
Ok. Thanks, but one thing I'm thinking is shouldn't it be quiet when abs is working? And feel nothing on ur feet? Which mean even the abs is working but we shouldn't feel it? I probably make another video and let you guys see.
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Tiny
Changchingchi
Oct 9, 2012.
As long as the ABS light in the dash is OFF while driving, the system is ON.

Once the ABS is Activated, you feel & hear the abs pump.

During normal daily driving, you should not hear / feel the ABS, simply
because it is not needed.

If the ABS light is always ON, then the ABS is Deactivated because a
fault is detected in the system.

Thomas

Tiny
Exovcds
Oct 9, 2012.
Hey, guys.

For this moment, I think the problems had been solved, at least I never feel anything in normal brake application. It is fine for me. What they did are checked all the abs sensors and reface the "all" rotors". Also, I asked them to disconnect the battery in order to reboot the whole system. I don't know which part worked, at least it is fine right now. Meanwhile, I was told the motor mounts for both sides are bad which make my car has vibration around 60-80 mph( I just finished the tire-balancing). So, I guess that will be my next thing to do.I am planning to change the motor mounts by myself. I searched so info online. I think it wont be that's hard to do, any idea? : )

Tiny
Changchingchi
Oct 10, 2012.

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